Optical instrument.



W. B. RAYTON & G. A. H. KELLNER.

OPTICAL INSTRUMENT.

APPLICATION FILED NOV. 8, 1913.

1,1 96,81 1 Patented Sept. 5, 1916.

m stares ra rnnr orrion.

WILBUR B. RAYTON AND GUSTAV A. HEBMANN KELLN ER, OF ROCHESTER, NEW YORK,

ASSIGN'ORS TO BAUSCH & 110MB OPTICAL COMPANY, OF BOG NEW YOBLK, A.

CORPORATION OF NEW YORK..

To all whom it may concern Be it known that we, WILBUR B. RAYTON and GUsTAv A. HERMANN KELLNER, both of Rochester, in the county of Monroe and State of New York, have invented certain deflecting the principal rays of the pencils of light so that they emerge from the ocular unsymmetrical with respect to the optical axis of the instrument, and therefore'intersect in a point which does not lie in the axis.

-The invention is particularly applicable to gun sights provided with the primary and secondary oculars and our invention is applied to instruments of this character to I provide a means whereby the center of area of one half the normal exit pupil is displaced sufiiciently 'to position it on the geometrical axis of the instrument.

To these and other ends the invention consists in certain improvements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawings: Figure 1 is a longitudinal sectional view of a two eyepiece gun sight illustrating a typ'e of apparatns'to which the present invention is applicable and showing .an arrangement of parts illus trating one embodiment of the invention; Fig. 2 is a horizontal sectional view taken along the axis of the lens system shown in Fig. 1, looking upwardly; Fig. 3 is a rear end view of a gun sight showing the eye shield; Figs. 4 and 5 are diagrammatic views of a telescope lllustrating a modification of the devices employed for carrying out the invention; Fig. 6 is a cross sectional- Speeificati on of Letters Patent.

invention relates to optical OPTICAL INSTRUMENT.

able prism inserted .in the instrument casing.

Similar reference numerals throughout general characteristics of those embodied in Umted States Letters Patent No. 991,652, granted May 9-, 1911 to George N. Saeg- Patented Sept. 5:, 15916. Application filed November 8, 1913. Serial No. 799,843. i

muller, for single field double sighting telescope. The means for shifting the centerof the exit pupil out of coincidence with the geometrical axis of the eyepiece is prismatic 1n its action and may be associated with one or both of the eyepieces of the telescope. The latter, generally described, comprises the tubular shell 1, having at its forward end the objective lens 2 and provided at its opposite extremity with the eyepiece or primary ocular 3. Between the eyepiece and the objective is located the erecting system of lenses comprising the collective and proecting lenses as shown secured in the mounting 4. The secondary ocular com-.

prising the independent systems of eyepiece lenses, indicated by 5, is arranged at an angle to the major longitudinal axis of the telescope and projects laterally from the tubular shell 1.

In this instrument a portion of each pencil of light upon emerging from theerecting system of lenses passes into the pentaprism 6, the faces'of'which are arranged at such angles that the rays entering the prisms are directed into the secondary ocular 5. The remaining portion of each pencil of light passes directly into the primary ocular and the partial pencils received'in both of the eyepieces produce a complete image of the object. The prism 6 is of sufficient thickness and so arranged as to intercept substantially onehalf of the light rays, consequently there is formed by each of the two oculars semicircular exit pupils, which may otherwise be described as half disks. Examining these half disks in their positions back of the eyepieces it will be observed that one of them lies wholly at one side of the axis of its lens system, while the other lies wholly at the opposite side of the axis of its respective lens system. The observer, or observers, viewing images in the two eyepieces, in order to seof the geometrical axes of the eyepieces.

' This is unnatural and occasions difliculty in latter it is a source of contlnual annoyance the proper sighting of the instrument onthe part of any but experienced users and to the as well as'a hindrance inthat it militates against the speedy use of the instrument, a fact of noteworthy importance in a gun sight employed for rapid fire cannon. On these telescopes it is customary to employ an eye cap attached to each eye-piece whichis madeof rubber and so shaped as to fit the 'observers face and center 'hiseye in respect to the geometrical center of the eye-piece. This cap adds to the difficulty of de-centering the eye as is necessary when looking into one half of the exit pupil, but it is qulte as important that the cap should be maintained m a centered position because the instrument may be frequently usedwithout the secondary ocular, in which event the penta- 'pri'sm is removed whereupon the eye must be centered with respect to the axis.

In Figs; 4 and 5, we have shown diagrammatically one embodiment of the, invention comprising two prisms 11 'and'12 of small an les, one of which is-rotatable by any suitabli adjusting device operable from the'exterior of the telescope casing. These prisms are shown in their preferred position in' the focal plane of the ocular. In their normal position, thetwo prisms occupy the position shown in Fig. 4 and their adjacent faces being in contact, no influence is effected to deflect the pencils of light rays. In Fig. 5,"

- the movable prismis illustrated in its operative position, having been rotated 4 through an angle of 180 so that, now the entrance andexit surfaces of the two prisms 11 and 12 lie at the required angle to shift the pencil of ray passing therethrough sufliciently to form the: semicircular exit pupil with its center of area in the geometrical axis of the eye-piece. Another means by which the ,invention may be accomplished is to employ a single lens of proper curvature offset relatively to the axis of the telescope or de-centered, and in Fig. 2, we have shown a lens 13 mounted '3 in this manner in a support 14 which is preferably adjustable laterally from the exterior of the casing by any suitable devices such as an operating pawl or handle 15. Ihe off setting or de-centering of the lens produces the same prismatic effect as is obtained by the use of the two prisms, and by arranging the lens 13 in an adjustable mounting it may be quickly shifted into a central position in respect to the other lenses of the instrument eye-piece instrument shifting-the exit incesii 1 whenever the latter is converted into a single 'by' the removal of the. pentaprism 6.

Asa further means of carrying out the invention and in-lieu of the two prisms, shown in Figs". 4 and 5, a single prism 12 may be is rotated into the position shown in Fig. 5..

The present invention of producing deviations of the pencil of light rays to shift the exit pupil laterally, is comprehensive and will be understood to include other means than those disclosed, which, however, commend themselves for all practical purposes because of their simplicity.

We claim as our invention:

1. In an optical instrument, the combinameans for producing a partial exit pupil at one side offthe eye-piece, and means for v pupil into the geometrical axis of the eye-piece. r

2. In'an optical instrument, the combina-' tion with an objective and an eyepiece having its axis at an angle to the axis of the objectiye, of means for producing a partial exit ppil at one side of the eye-piece, and means for shifting the exit pupil into the geometrical axis of theeye-piece.

3. In an optical instrument, the combination with an objective, an eye-piece and an used, the adj usta'bility of which, for the pur .pose of accomplishing the desired result, is

tion with anob'jective and an eye-piece, of 1 erecting system of lenses located between said parts, of means located in rear of the erecting system for producing a. partial exit pupil at one side of the eyeiece and means for shifting the exit pup into the geometrical axis of the eye-piece.

4. In an optical instrument, the combination with an objective and an eye-piece, of means for normally producing-a partial exit pupil at one side of theeye-piece, and two prisms interposed between the eye-piece and said means, one of which is adjustable to shift'the exit pupil into the geometrical axis of the eye-piece.

5. An optical instrument comprising an objective, a primary and a secondary ocular, meansfor deflecting a portion of the light rays into the secondary ocular, and/ means for shifting the center of area of the semirays into the secondary ocular, and means and out of the optical axis of the instrument associated with each ocular for shifting the and serving to shift the center of area of thecenter of area of each seini-circular exit exit pupil of one of the ocularsinto the geopnpil into the geometrical axis of its respecmetrical axis of said ocular.

5 tive ocular.

1 WILBUR B. RAY'I'ON. 7. In an OPtlCai instrument, the combma- GUSTAV HERMANN KELLNER tion with an objective, a primary and a secondary ocular andmeans for deflecting a Witnesses:

portion of the light rays into the secondary WILLIAM G. WOODWORTH,

10 ocular, of refracting means adjustable 'into HENRY C. THOM.. 

